ALMA Communicator – DNS Tunneling Trojan

ALMA Communicator is a backdoor trojan created by the state-sponsored OilRig group that uses DNS tunnelling to receive commands and exfiltrate data.

Threat ID:: CC-1795
Category:: Trojan
Threat Severity:: Medium
Threat Vector:: Macro, Download
Published:: 16 November 2017 12:00 AM

Report a cyber attack: call 0300 303 5222 or email [email protected]

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Summary

ALMA Communicator is a backdoor trojan created by the state-sponsored OilRig group that uses DNS tunnelling to receive commands and exfiltrate data.

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

Microsoft Windows – all versions

Threat details

It is delivered by a specially crafted Excel document (called “Clayslide” by OilRig) that contains malicious macros. When opened, this file asks users to enable extra content before executing the macros and dropping ALMA on the system. It is important to note that ALMA has no internal configuration, instead relying on the Clayslide file for this.

As it communicates using DNS requests, ALMA can only handle very limited volumes of data (download 10 bytes and upload 4 bytes per request). As such, any sizeable amount of data will generate a large number of DNS request, potentially alerting a user to an infection.

Remediation advice

To prevent and detect a trojan infection, ensure that:

Remediation steps

Type	Step
	A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails. All operating systems, antivirus and other security products are kept up to date. All day to day computer activities such as email and internet are performed using non-administrative accounts. Strong password policies are in place and password reuse is discouraged. Network, proxy and firewall logs should be monitored for suspicious activity. User accounts accessed from infected machines should be reset on a clean computer

Type

Step

A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
All operating systems, antivirus and other security products are kept up to date.
All day to day computer activities such as email and internet are performed using non-administrative accounts.
Strong password policies are in place and password reuse is discouraged.
Network, proxy and firewall logs should be monitored for suspicious activity.
User accounts accessed from infected machines should be reset on a clean computer

Last edited: 17 February 2020 11:25 am